Mobile Ad Hoc Networks Exploiting Multi-Beam Antennas

Mobile Ad Hoc Networks Exploiting Multi-Beam Antennas

Yimin Zhang (Villanova University, USA), Xin Li (Villanova University, USA) and Moeness G. Amin (Villanova University, USA)
DOI: 10.4018/978-1-59904-988-5.ch019
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This chapter introduces the concept of multi-beam antenna (MBA) in mobile ad hoc networks and the recent advances in the research relevant to this topic. MBAs have been proposed to achieve concurrent communications with multiple neighboring nodes while they inherit the advantages of directional antennas, such as the high directivity and antenna gain. MBAs can be implemented in the forms of multiple fixed-beam directional antennas (MFBAs) and multi-channel smart antennas (MCSAs). The former either uses multiple predefined beams or selects multiple directional antennas and thus is relatively simple; the latter uses smart antenna techniques to dynamically form multiple adaptive beams and thereby provides more robust communication links to the neighboring nodes. The emphases of this chapter lie in the offerings and implementation techniques of MBAs, random-access scheduling for the contention resolution, effect of multipath propagation, and node throughput evaluation.
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I. Introduction

Traditional wireless networks require single-hop wireless connectivity to the wired network. Recently, mobile ad hoc networks have yielded considerable advances to support communications among a group of mobile hosts where no wired backbone infrastructure is available (Lal, 2004; Choudhury, 2006; Ramanathan, 2005). User nodes in ad hoc networks traditionally employ omnidirectional antennas, where a transmission on a given channel requires all other nodes in range keep silent or use alternative channels with a different time slot, frequency, or spreading code. As such, the use of omnidirectional antennas does not provide effective channel use and, subsequently, wastes a large portion of the network capacity (Huang, 2002a; Bandyopadhyay, 2006). Incorporation of directional antennas has been proposed to achieve improved network capacity and quality of service. Compared to omnidirectional antennas, directional antennas have higher directivity and antenna gain. Therefore, directional antennas not only significantly reduce the power necessary for the service coverage and packet transmission, but also mitigate the interference in the directions away from that of the desired users. As a result, the use of directional antennas provides a platform to serve increased number of nodes and network throughput. The antenna gain due to directional transmission and reception enables extended communication range of each hop, thereby reducing the number of hops between distant source and sink nodes, and increasing the efficiency and reliability of the network (Ko, 2000; Nasipuri, 2000; Wang, 2002; Zhang, 2005).

A directional antenna with a single beam, however, does not fully utilize the offering of multi-sensor systems. In addition, the deployment of directional antennas may result in new problems. For example, the deafness problem appears when a node is tuned to a specific direction and thus cannot hear a node in another direction, even they are closely located. The deafness problem not only impedes dynamic resource allocation, but also increases the possibility of network outage for certain services (Choudhury, 2004; Jain, 2006a). To mitigate the deafness problem and enhance the network capacity, multi-beam antennas (MBAs) have been proposed to achieve concurrent communications with multiple neighboring nodes while inheriting the advantages of directional antennas, such as the high directivity and antenna gain. MBAs can be implemented in the forms of multiple fixed-beam directional antennas (MFBAs) and multi-channel smart antennas (MCSAs). To form multiple fixed-beams, MFBAs and multiple radios (MRs) with a directional antenna equipped in each radio can be exploited (Bahl, 2004; Draves, 2004). As a result, high network throughput can be achieved. In a stationary environment, the antenna patterns can be optimized to further improve network performance. However, the performance of MFBAs and MRs degrades in a time-varying multipath propagation environment, which is typically experienced in indoor and low-altitude outdoor wireless networks (Winters, 2006).

Another approach to implement MBAs is to use MCSAs (Singh, 2005; Zhang, 2006; Li, 2007). By using smart antenna techniques, multiple beams can be adaptively and dynamically formed by a node so as to provide robust communication links with multiple users. At the expense of higher complexity, an MCSA-based approach takes the same advantages as the MFBA implementation, but its performance does not degrade in time-varying multipath environment (Zhang, 2006; Li, 2007).

The purpose of this chapter is to discuss the recent advances of MBA approaches for wireless ad hoc network applications. To bridge the gap between omnidirectional antennas and MBAs, the concept and offerings of ad hoc networks with directional antennas are first reviewed and a brief introduction of the medium access control (MAC) protocols and routing approaches developed for directional antennas is provided. Beamforming techniques and random-access scheduling (RAS) schemes in the contention resolution are then introduced. The respective node throughput performance and probability of concurrent communications are examined using a simplified ideal sector-based model as well as a precise output signal-to-interference-plus-noise ratio (SINR) based model.

Complete Chapter List

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Table of Contents
Jack H. Winters
Chen Sun, Jun Cheng, Takashi Ohira
Chapter 1
Constantin Siriteanu, Steven D. Blostein
This chapter unifies the principles and analyses of conventional signal processing algorithms for receive-side smart antennas, and compares their... Sample PDF
Eigencombining: A Unified Approach to Antenna Array Signal Processing
Chapter 2
Zhu Liang Yu, Meng Hwa Er, Wee Ser, Chen Huawei
In this chapter, we first review the background, basic principle and structure of adaptive beamformers. Since there are many robust adaptive... Sample PDF
Robust Adaptive Beamforming
Chapter 3
Sheng Chen
Adaptive beamforming is capable of separating user signals transmitted on the same carrier frequency, and thus provides a practical means of... Sample PDF
Adaptive Beamforming Assisted ReceiverAdaptive Beamforming
Chapter 4
Thomas Hunziker
Many common adaptive beamforming methods are based on a sample matrix inversion (SMI). The schemes can be applied in two ways. The sample covariance... Sample PDF
On the Employment of SMI Beamforming for Cochannel Interference Mitigation in Digital Radio
Chapter 5
Hideki Ochiai, Patrick Mitran, H. Vincent Poor, Vahid Tarokh
In wireless sensor networks, the sensor nodes are often randomly situated, and each node is likely to be equipped with a single antenna. If these... Sample PDF
Random Array Theory and Collaborative Beamforming
Chapter 6
W. H. Chin, C. Yuen
Space-time block coding is a way of introducing multiplexing and diversity gain in wireless systems equipped with multiple antennas. There are... Sample PDF
Advanced Space-Time Block Codes and Low Complexity Near Optimal Detection for Future Wireless Networks
Chapter 7
Xiang-Gen Xia, Genyuan Wang, Pingyi Fan
Modulated codes (MC) are error correction codes (ECC) defined on the complex field and therefore can be naturally combined with an intersymbol... Sample PDF
Space-Time Modulated Codes for MIMO Channels with Memory
Chapter 8
Javier Vía, Ignacio Santamaría, Jesús Ibáñez
This chapter analyzes the problem of blind channel estimation under Space-Time Block Coded transmissions. In particular, a new blind channel... Sample PDF
Blind Channel Estimation in Space-Time Block Coded Systems
Chapter 9
Chen Sun, Takashi Ohira, Makoto Taromaru, Nemai Chandra Karmakar, Akifumi Hirata
In this chapter, we describe a compact array antenna. Beamforming is achieved by tuning the load reactances at parasitic elements surrounding the... Sample PDF
Fast Beamforming of Compact Array Antenna
Chapter 10
Eddy Taillefer, Jun Cheng, Takashi Ohira
This chapter presents direction of arrival (DoA) estimation with a compact array antenna using methods based on reactance switching. The compact... Sample PDF
Direction of Arrival Estimation with Compact Array Antennas: A Reactance Switching Approach
Chapter 11
Santana Burintramart, Nuri Yilmazer, Tapan K. Sarkar, Magdalena Salazar-Palma
This chapter presents a concern regarding the nature of wireless communications using multiple antennas. Multi-antenna systems are mainly developed... Sample PDF
Physics of Multi-Antenna Communication Systems
Chapter 12
MIMO Beamforming  (pages 240-263)
Qinghua Li, Xintian Eddie Lin, Jianzhong ("Charlie") Zhang
Transmit beamforming improves the performance of multiple-input multiple-output antenna system (MIMO) by exploiting channel state information (CSI)... Sample PDF
MIMO Beamforming
Chapter 13
Biljana Badic, Jinho Choi
This chapter introduces joint beamforming (or precoding) and space-time coding for multiple input multiple output (MIMO) channels. First, we explain... Sample PDF
Joint Beamforming and Space-Time Coding for MIMO Channels
Chapter 14
Zhendong Zhou, Branka Vucetic
This chapter introduces the adaptive modulation and coding (AMC) as a practical means of approaching the high spectral efficiency theoretically... Sample PDF
Adaptive MIMO Systems with High Spectral Efficiency
Chapter 15
Joakim Jaldén, Björn Ottersten
This chapter takes a closer look at a class of MIMO detention methods, collectively referred to as relaxation detectors. These detectors provide... Sample PDF
Detection Based on Relaxation in MIMO Systems
Chapter 16
Wolfgang Utschick, Pedro Tejera, Christian Guthy, Gerhard Bauch
This chapter discusses four different optimization problems of practical importance for transmission in point to multipoint networks with a multiple... Sample PDF
Transmission in MIMO OFDM Point to Multipoint Networks
Chapter 17
Salman Durrani, Marek E. Bialkowski
This chapter discusses the use of smart antennas in Code Division Multiple Access (CDMA) systems. First, we give a brief overview of smart antenna... Sample PDF
Smart Antennas for Code Division Multiple Access Systems
Chapter 18
Aimin Sang, Guosen Yue, Xiaodong Wang, Mohammad Madihian
In this chapter, we consider a cellular downlink packet data system employing the space-time block coded (STBC) multiple- input-multiple-output... Sample PDF
Cross-Layer Performance of Scheduling and Power Control Schemes in Space-Time Block Coded Downlink Packet Systems
Chapter 19
Yimin Zhang, Xin Li, Moeness G. Amin
This chapter introduces the concept of multi-beam antenna (MBA) in mobile ad hoc networks and the recent advances in the research relevant to this... Sample PDF
Mobile Ad Hoc Networks Exploiting Multi-Beam Antennas
Chapter 20
Toru Hashimoto, Tomoyuki Aono
The technology of generating and sharing the key as the representative application of smart antennas is introduced. This scheme is based on the... Sample PDF
Key Generation System Using Smart Antenna
Chapter 21
Nemai Chandra Karmakar
Various smart antennas developed for automatic radio frequency identification (RFID) readers are presented. The main smart antennas types of RFID... Sample PDF
Smart Antennas for Automatic Radio Frequency Identification Readers
Chapter 22
Konstanty Bialkowski, Adam Postula, Amin Abbosh, Marek Bialkowski
This chapter introduces the concept of Multiple Input Multiple Output (MIMO) wireless communication system and the necessity to use a testbed to... Sample PDF
Field Programmable Gate Array Based Testbed for Investigating Multiple Input Multiple Output Signal Transmission in Indoor Environments
Chapter 23
Masahiro Watanabe, Sadao Obana, Takashi Watanabe
Recent studies on directional media access protocols (MACs) using smart antennas for wireless ad hoc networks have shown that directional MACs... Sample PDF
Ad Hoc Networks Testbed Using a Practice Smart Antenna with IEEE802.15.4 Wireless Modules
Chapter 24
Monthippa Uthansakul, Marek E. Bialkowski
This chapter introduces the alternative approach for wideband smart antenna in which the use of tapped-delay lines and frequency filters are... Sample PDF
Wideband Smart Antenna Avoiding Tapped-Delay Lines and Filters
Chapter 25
Jun Cheng, Eddy Taillefer, Takashi Ohira
Three working modes, omni-, sector and adaptive modes, for a compact array antenna are introduced. The compact array antenna is an electronically... Sample PDF
Omni-, Sector, and Adaptive Modes of Compact Array Antenna
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